Pen



FIG. 1. is a perspective view thereof;

FIG. 2. is a front elevational view thereof;

FIG. 3. is a rear elevational view thereof;

FIG. 4. is a left side elevational view thereof;

FIG. 5. is a right side elevational view thereof;

FIG. 6. is a top plan view thereof; and,

FIG. 7. is a bottom plan view thereof.

The broken-line showing of a portion of a writing instrument in FIGS. 1–5 in the drawings is environmental matter and forms no part of the claimed design. The broken-line circle in FIG. 7 defines the bounds of the claimed design and forms no part thereof. 

The ornamental design for a pen, as shown and described. 